The invention relates to a tube- or hose connector for the transport of a fluid having at least at one end a ring type nipple with a cross hole, which serves to mount the connector at an aggregate for receiving a banjo bolt having a head and a threaded shank as well as two gaskets. A tube- or hose connector is understood to be a piece of tube or hose, which has at least at one end, preferably at both ends, though, connections to connect aggregates to each other. A pump can be connected to a cylinder with such a connector, for instance. The connector can have a piece of a tube, as well as a piece of a hose. The piece of the tube can be comparably short and can consist of just a nipple. A fluid is understood to be liquid or gaseous medium, which is sent through the connector in its mounted state. Tube-or hose connector of the type in question are used especially in the automotive industry, e.g. for power steering devices, air conditioning units, cooling units, etc. For this the individual aggregates have to be connected to each other with such a connector. Connnectors with connections that extend at right angles from or to the aggregates and protrude as little as possible are used in these cases, because cramped assembly conditions occur during the automotive manufacturing process. Especially useful to this end are connectors with connections that have a ring type nipple according to DIN 76 42, a banjo bolt according to DIN 76 43, as well as the accompanying gaskets. This type of tube- or hose connectors are concerned here.
Known tube- or hose connectors of the type described above have at least at one end a ring type nipple with a cross hole. The ring type nipple is attached to the piece of tube, especially by soldering, by which the interior of the tube is connected to the interior of the ring type nipple with the cross hole. The cross hole extends through the ring type nipple at a right angle with respect to the piece of tube and ends in sealing surfaces. These sealing surfaces are provided with two protecting covers at the manufacturer of the tube- or hose connector to prevent a damage of the sealing surfaces during the transport to the automotive factory. The tube- or hose connectors, banjo bolts, and gaskets are supplied seperately to the automotive factory. For the assembly the connector is taken and the two protecting covers are removed from the ring type nipple. Then a banjo bolt is taken, a gasket is put onto it, and the banjo bolt with the gasket is stuck through the cross hole of the ring type nipple. Afterwards a second gasket is put onto the threaded shank of the banjo bolt. The in this way preassembled unit is held with one hand at the tube or hose of the connector, while the other hand holds the banjo bolt with the two gaskets at the ring type nipple. Due to the often relatively far extending connectors and the cramped assembly conditions the following assembly of the connector is highly dependent on the skill of the mechanic. First the axis of the banjo bolt has to be aligned to the axis of the screw socket of the aggregate, and in this aligned position the banjo bolt must carefully be screwed in by one or two turns until the threads hold. Finally the banjo bolt is tightened with the aid of a tool-- usually with a predetermined torque--in such a way that a fluid tight connection is obtained. During this assembly there is the danger that the banjo bolt retreats somewhat from the ring type nipple, so that the banjo bolt and/or at least the gasket on the threaded shank side fall down. Especially when only the gasket falls down this is usually not noticed and a fluid tight connection cannot be obtained anymore. The falling down of the banjo bolt often damages its thread, so that a second attempt to screw it in becomes difficult. The aggregates into the screw sockets of which the banjo bolt is screwed are often made of aluminum, a relatively soft material, so that in the second attempt to screw in the banjo bolt a seizure can occur, of which the mechanic does not know whether it is caused by a damage to the thread of the banjo bolt or because of a misaligned thread of the banjo bolt in the screw socket. In most cases he will assume the first cause is responsible and will use a tool to forcibly screw in the banjo bolt. In the soft material of the aggregate this is possible even when the axes of the threads are not aligned. A fluid tight connection is not attainable under these circumstances. Rather than that the screw socket of the aggregate, e.g. the pump of the power steering, will be damaged by this forced screwing-in. The damage caused by this is appreciable. The pump has to be removed at the end of the conveyor and replaced by a new pump, the consequences of the loss of the pressure medium have to be eliminated as well. In some cases the housing of the pump can be refinished. Often the complete pump must be installed in a new housing, though. The falling down of the gasket at the threaded shank side also happens without a retreating of the banjo bolt especially when the connector must be mounted in such a relative position that the threaded shank of the banjo bolt is pointed downwards. In these cases the little finger of one hand is used to prevent the falling down of this gasket. The falling down of the banjo bolt and/or the gasket is often also connected with a contamination. By this not only the sealing surfaces are affected, but also the interior of the connector, which should actually have been protected by the two protecting covers. These protecting covers have to be removed prior to the assembly in order to form the preassembled unit.
Furthermore the use of protecting caps on threaded parts is known. These protecting caps are screwed or pressed into the connecting sleeve in the case of inside threads. In the case of outside threads the protecting caps are stuck onto the threaded part. They serve to protect the threaded part during the transport. They have to be removed prior to mounting the part concerned.
The U.S. Pat. No. 4 775 174 shows a tube- or hose connector for the transport of a fluid, which at one end has a ring type nipple with a cross hole, which serves to mount the connector at an aggregate for receiving a banjo bolt having a head and a threated shank as well as two gaskets, where the ring type nipple, the banjo bolt, and the gasket form a preassembled unit. The banjo bolt is held in its preassembled position by a metal retainer ring, by which the gasket at the head side of the banjo bolt is secured as well. For the securing of the other gasket a groove is provided in the banjo bolt close to the threaded shank. With this preassembled unit it is not clear, however, how the retainer ring gets into the interior of the ring type nipple and into its groove provided on the shank of the banjo bolt.